"Under VRAINS", known as "Doorway to the Abyss" in the Japanese version, is the thirtieth episode of the Yu-Gi-Oh! VRAINS anime. It first aired in Japan on December 6, 2017, became available with official subtitles via Crunchyroll on the same day, and aired in Canada on December 9, 2018.

Yusaku questions why Varis didn't show up at all during the Deleted Incident. In order to clear things up, he enters LINK VRAINS to investigate. There, he runs into Ghost Gal, who is also investigating something. The two then discover a place where something abnormal is happening...